Investigation of structural and mechanical properties of silicon carbonitride thin films

Abstract

Silicon Carbo-nitride (SiCN) thin films were deposited by using SiC and Si3N4 powder, and H2 and N2 as carrier gases by thermal chemical vapor deposition (CVD) on p-Si(100) substrates. The morphology, chemical bonding, structural analysis and mechanical properties of SiCN thin films were characterized by Atomic Force Microscope (AFM), Fourier Transform Infrared Spectroscopy (FTIR), Raman Spectroscopy, X-Ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and nanoindentation techniques respectively. The AFM images reveal that the surface roughness of SiCN thin films decreased with increasing H2 flow rate. The Raman signature at 937 to 967 cm−1 indicated formations of SiCN phase in the SiCN thin films with an increase in H2 flow rate. The FTIR results indicated SiC and SiCN bonds were prominent bonding in the SiCN thin films. The XRD results reveal the crystallite size of (102) planes and lattice strain of SiCN thin films varied from 13.29 to 2.93 nm and +0.02328 to 0.00439 with variation in the H2 flow rate from 40 to 120 sccm. The estimated composition of Si, and N in the SiCN thin film was varied from 29.7 to 30.7 and 31.7 to 33.9 at. % respectively, moreover, carbon composition, decreased by 38.5 to 35.7 at. % respectively by increasing of H2 flow rate. Hardness and modulus of SiCN thin films 30 GPa and 300 GPa with an elastic recovery of 64–68% were achieved.